The present invention relates to an information recording and reproducing apparatus, and particularly relates to a card holding unit of the information recording and reproducing apparatus for holding an information card on a card carriage.
In information recording and reproducing apparatuses using an information card, such as an optical card, the information card is held on a card carriage, which makes linear reciprocal relative movement in a direction perpendicular to the optical head, so that data tracks on the information card are scanned for recording and reproducing the information. (see Japanese patent unexamined laid-open or kokai publication No. 64 (1989)-1183, for example)
To correctly record information in and reproduce information from an information card in such a kind of information recording and reproducing apparatus, it is necessary to focus accurately a beam of light irradiated from the optical head to an information area of the information card. For this purpose the position of the focusing lens is usually controlled by focusing servo.
There is however a controllable range in the control of the control means such as the focusing servo, and hence the distance between the optical head and the information card must be kept substantially constant so that the dispersion in the distance in the whole information areas is included within the controllable range of the control means.
As shown in FIG. 7, to hold an information card 50 on a card carriage 51 according to the prior art, card holding plates 53a and 53b are supported on respective lateral edges of the card carriage 51 in a cantilever fashion, and guiding and holding grooves 52a and 52b are formed between the card holding plates 53a and 53b and the upper surface 51a of the card carriage 51, respectively. The information card 50 inserted into the grooves 52a and 52b is depressed and held at the upper surface 50a thereof by projections 54a and 54b of the card holding plates 53a and 53b.
In this information recording and reproducing apparatus, it is, however, impossible to keep the distance between the upper surface 50a of the information card 50 and the optical head at a predetermined value when as shown in FIG. 7, the information card 50 is considerably bent upwardly. In this case, information cannot be correctly recorded in or reproduced from the information card 50.